<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Cache\Driver;

use Think\Cache;

defined ( 'THINK_PATH' ) or exit ();

/**
 * Redis缓存驱动
 * 要求安装phpredis扩展：https://github.com/nicolasff/phpredis
 */
class Redis extends Cache {
	/**
	 * 架构函数
	 * 
	 * @param array $options
	 *        	缓存参数
	 * @access public
	 */
	public function __construct($options = array()) {
		if (! extension_loaded ( 'redis' )) {
			E ( L ( '_NOT_SUPPORT_' ) . ':redis' );
		}
		$options = array_merge ( array (
				'host' => C ( 'REDIS_HOST' ) ?  : '127.0.0.1',
				'port' => C ( 'REDIS_PORT' ) ?  : 6379,
				'timeout' => C ( 'DATA_CACHE_TIMEOUT' ) ?  : false,
				'persistent' => false 
		), $options );
		
		$this->options = $options;
		$this->options ['expire'] = isset ( $options ['expire'] ) ? $options ['expire'] : C ( 'DATA_CACHE_TIME' );
		$this->options ['prefix'] = isset ( $options ['prefix'] ) ? $options ['prefix'] : C ( 'DATA_CACHE_PREFIX' );
		$this->options ['length'] = isset ( $options ['length'] ) ? $options ['length'] : 0;
		$func = $options ['persistent'] ? 'pconnect' : 'connect';
		$this->handler = new \Redis ();
		$options ['timeout'] === false ? $this->handler->$func ( $options ['host'], $options ['port'] ) : $this->handler->$func ( $options ['host'], $options ['port'], $options ['timeout'] );
	}
	
	/**
	 * 读取缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @return mixed
	 */
	public function get($name) {
		N ( 'cache_read', 1 );
		$value = $this->handler->get ( $this->options ['prefix'] . $name );
		$jsonData = json_decode ( $value, true );
		return ($jsonData === NULL) ? $value : $jsonData; // 检测是否为JSON数据 true 返回JSON解析数组, false返回源数据
	}
	
	/**
	 * 写入缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @param mixed $value
	 *        	存储数据
	 * @param integer $expire
	 *        	有效时间（秒）
	 * @return boolean
	 */
	public function set($name, $value, $expire = null) {
		N ( 'cache_write', 1 );
		if (is_null ( $expire )) {
			$expire = $this->options ['expire'];
		}
		$name = $this->options ['prefix'] . $name;
		// 对数组/对象数据进行缓存处理，保证数据完整性
		$value = (is_object ( $value ) || is_array ( $value )) ? json_encode ( $value ) : $value;
		if (is_int ( $expire ) && $expire) {
			$result = $this->handler->setex ( $name, $expire, $value );
		} else {
			$result = $this->handler->set ( $name, $value );
		}
		if ($result && $this->options ['length'] > 0) {
			// 记录缓存队列
			$this->queue ( $name );
		}
		return $result;
	}
	
	/**
	 * 删除缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @return boolean
	 */
	public function rm($name) {
		return $this->handler->delete ( $this->options ['prefix'] . $name );
	}
	
	/**
	 * 清除缓存
	 * 
	 * @access public
	 * @return boolean
	 */
	public function clear() {
		return $this->handler->flushDB ();
	}
}
